Sonographic findings of spina bifidaMost common site is lumbosacral region. Ventriculomegaly with hydrocephalus. Banana sign - cerebellum is stretched around the brain stem with effacement of cisterna magna. Lemon sign - Flattening of frontal bones on transverse image. Bony defect in spine: - V shaped profile due to outward flaring of two posterior ossification centres. Presence of intact sac on posterior aspect of spine. Sac filled with fluid or solid tissue in meningocele or myelomeningocele.